[PATCH 0/7] scripts/gdb: Updates for 4.2

[PATCH 0/7] scripts/gdb: Updates for 4.2

[Jan Kiszka]

Hi Andrew,

please include the following enhancements, fixes and cleanups for the
gdb scripts in your queue. Most work was done by Thiébaud, adding a list
checker and basic process listing.

Jan


CC: =?UTF-8?q?Thi=C3=A9baud=20Weksteen?= <thiebaud@weksteen.fr>

Jan Kiszka (2):
  scripts/gdb: Also allow list_head pointer as lx-list-check paramter
  scripts/gdb: Enable completion for lx-list-check parameter

Thiébaud Weksteen (5):
  scripts/gdb: Add command to check list consistency
  scripts/gdb: Fix typo in exception name
  scripts/gdb: Fix PEP8 compliance
  scripts/gdb: Add ps command
  scripts/gdb: Remove useless global instruction

 scripts/gdb/linux/dmesg.py   |  1 -
 scripts/gdb/linux/lists.py   | 92 ++++++++++++++++++++++++++++++++++++++++++++
 scripts/gdb/linux/symbols.py |  9 ++---
 scripts/gdb/linux/tasks.py   | 20 +++++++++-
 scripts/gdb/linux/utils.py   |  4 +-
 scripts/gdb/vmlinux-gdb.py   |  1 +
 6 files changed, 117 insertions(+), 10 deletions(-)
 create mode 100644 scripts/gdb/linux/lists.py

-- 
2.1.4

[PATCH 1/7] scripts/gdb: Add command to check list consistency

[Jan Kiszka]

From: Thiébaud Weksteen <thiebaud@weksteen.fr>

Add a gdb script to verify the consistency of lists.

Signed-off-by: Thiébaud Weksteen <thiebaud@weksteen.fr>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 scripts/gdb/linux/lists.py | 89 ++++++++++++++++++++++++++++++++++++++++++++++
 scripts/gdb/vmlinux-gdb.py |  1 +
 2 files changed, 90 insertions(+)
 create mode 100644 scripts/gdb/linux/lists.py

diff --git a/scripts/gdb/linux/lists.py b/scripts/gdb/linux/lists.py
new file mode 100644
index 0000000..2a94b54
--- /dev/null
+++ b/scripts/gdb/linux/lists.py
@@ -0,0 +1,89 @@
+#
+# gdb helper commands and functions for Linux kernel debugging
+#
+#  list tools
+#
+# Copyright (c) Thiebaud Weksteen, 2015
+#
+# Authors:
+#  Thiebaud Weksteen <thiebaud@weksteen.fr>
+#
+# This work is licensed under the terms of the GNU GPL version 2.
+#
+
+import gdb
+
+from linux import utils
+
+list_head = utils.CachedType("struct list_head")
+
+
+def list_check(head):
+    nb = 0
+    c = head
+    if (c.type != list_head.get_type()):
+        raise gdb.GdbError('The argument should be of type (struct list_head)')
+    try:
+        gdb.write("Starting with: {}\n".format(c))
+    except gdb.MemoryError:
+        gdb.write('head is not accessible\n')
+        return
+    while True:
+        p = c['prev'].dereference()
+        n = c['next'].dereference()
+        try:
+            if p['next'] != c.address:
+                gdb.write('prev.next != current: '
+                          'current@{current_addr}={current} '
+                          'prev@{p_addr}={p}\n'.format(
+                              current_addr=c.address,
+                              current=c,
+                              p_addr=p.address,
+                              p=p,
+                          ))
+                return
+        except gdb.MemoryError:
+            gdb.write('prev is not accessible: '
+                      'current@{current_addr}={current}\n'.format(
+                          current_addr=c.address,
+                          current=c
+                      ))
+            return
+        try:
+            if n['prev'] != c.address:
+                gdb.write('next.prev != current: '
+                          'current@{current_addr}={current} '
+                          'next@{n_addr}={n}\n'.format(
+                              current_addr=c.address,
+                              current=c,
+                              n_addr=n.address,
+                              n=n,
+                          ))
+                return
+        except gdb.MemoryError:
+            gdb.write('next is not accessible: '
+                      'current@{current_addr}={current}\n'.format(
+                          current_addr=c.address,
+                          current=c
+                      ))
+            return
+        c = n
+        nb += 1
+        if c == head:
+            gdb.write("list is consistent: {} node(s)\n".format(nb))
+            return
+
+
+class LxListChk(gdb.Command):
+    """Verify a list consistency"""
+
+    def __init__(self):
+        super(LxListChk, self).__init__("lx-list-check", gdb.COMMAND_DATA)
+
+    def invoke(self, arg, from_tty):
+        argv = gdb.string_to_argv(arg)
+        if len(argv) != 1:
+            raise gdb.GdbError("lx-list-check takes one argument")
+        list_check(gdb.parse_and_eval(argv[0]))
+
+LxListChk()
diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py
index 4848928..ce82bf5 100644
--- a/scripts/gdb/vmlinux-gdb.py
+++ b/scripts/gdb/vmlinux-gdb.py
@@ -28,3 +28,4 @@ else:
     import linux.dmesg
     import linux.tasks
     import linux.cpus
+    import linux.lists
-- 
2.1.4

[PATCH 2/7] scripts/gdb: Also allow list_head pointer as lx-list-check paramter

[Jan Kiszka]

This makes the usage more flexible.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 scripts/gdb/linux/lists.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/scripts/gdb/linux/lists.py b/scripts/gdb/linux/lists.py
index 2a94b54..71fba6a 100644
--- a/scripts/gdb/linux/lists.py
+++ b/scripts/gdb/linux/lists.py
@@ -20,9 +20,11 @@ list_head = utils.CachedType("struct list_head")
 
 def list_check(head):
     nb = 0
+    if (head.type == list_head.get_type().pointer()):
+        head = head.dereference()
+    elif (head.type != list_head.get_type()):
+        raise gdb.GdbError('argument must be of type (struct list_head [*])')
     c = head
-    if (c.type != list_head.get_type()):
-        raise gdb.GdbError('The argument should be of type (struct list_head)')
     try:
         gdb.write("Starting with: {}\n".format(c))
     except gdb.MemoryError:
-- 
2.1.4

[PATCH 3/7] scripts/gdb: Enable completion for lx-list-check parameter

[Jan Kiszka]

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 scripts/gdb/linux/lists.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/scripts/gdb/linux/lists.py b/scripts/gdb/linux/lists.py
index 71fba6a..3a3775b 100644
--- a/scripts/gdb/linux/lists.py
+++ b/scripts/gdb/linux/lists.py
@@ -80,7 +80,8 @@ class LxListChk(gdb.Command):
     """Verify a list consistency"""
 
     def __init__(self):
-        super(LxListChk, self).__init__("lx-list-check", gdb.COMMAND_DATA)
+        super(LxListChk, self).__init__("lx-list-check", gdb.COMMAND_DATA,
+                                        gdb.COMPLETE_EXPRESSION)
 
     def invoke(self, arg, from_tty):
         argv = gdb.string_to_argv(arg)
-- 
2.1.4

[PATCH 4/7] scripts/gdb: Fix typo in exception name

[Jan Kiszka]

From: Thiébaud Weksteen <thiebaud@weksteen.fr>

Signed-off-by: Thiébaud Weksteen <thiebaud@weksteen.fr>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 scripts/gdb/linux/utils.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/gdb/linux/utils.py b/scripts/gdb/linux/utils.py
index 128c306..d7ff3a3 100644
--- a/scripts/gdb/linux/utils.py
+++ b/scripts/gdb/linux/utils.py
@@ -83,7 +83,7 @@ def get_target_endianness():
         elif "big endian" in endian:
             target_endianness = BIG_ENDIAN
         else:
-            raise gdb.GdgError("unknown endianness '{0}'".format(str(endian)))
+            raise gdb.GdbError("unknown endianness '{0}'".format(str(endian)))
     return target_endianness
 
 
-- 
2.1.4

[PATCH 5/7] scripts/gdb: Fix PEP8 compliance

[Jan Kiszka]

From: Thiébaud Weksteen <thiebaud@weksteen.fr>

Signed-off-by: Thiébaud Weksteen <thiebaud@weksteen.fr>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 scripts/gdb/linux/dmesg.py   | 1 -
 scripts/gdb/linux/symbols.py | 9 ++++-----
 scripts/gdb/linux/tasks.py   | 2 ++
 scripts/gdb/linux/utils.py   | 2 +-
 4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/scripts/gdb/linux/dmesg.py b/scripts/gdb/linux/dmesg.py
index 3c947f0..927d0d2 100644
--- a/scripts/gdb/linux/dmesg.py
+++ b/scripts/gdb/linux/dmesg.py
@@ -12,7 +12,6 @@
 #
 
 import gdb
-import string
 
 from linux import utils
 
diff --git a/scripts/gdb/linux/symbols.py b/scripts/gdb/linux/symbols.py
index cd5bea9..627750c 100644
--- a/scripts/gdb/linux/symbols.py
+++ b/scripts/gdb/linux/symbols.py
@@ -14,9 +14,8 @@
 import gdb
 import os
 import re
-import string
 
-from linux import modules, utils
+from linux import modules
 
 
 if hasattr(gdb, 'Breakpoint'):
@@ -97,7 +96,7 @@ lx-symbols command."""
             return ""
         attrs = sect_attrs['attrs']
         section_name_to_address = {
-            attrs[n]['name'].string() : attrs[n]['address']
+            attrs[n]['name'].string(): attrs[n]['address']
             for n in range(int(sect_attrs['nsections']))}
         args = []
         for section_name in [".data", ".data..read_mostly", ".rodata", ".bss"]:
@@ -124,7 +123,7 @@ lx-symbols command."""
                 addr=module_addr,
                 sections=self._section_arguments(module))
             gdb.execute(cmdline, to_string=True)
-            if not module_name in self.loaded_modules:
+            if module_name not in self.loaded_modules:
                 self.loaded_modules.append(module_name)
         else:
             gdb.write("no module object found for '{0}'\n".format(module_name))
@@ -164,7 +163,7 @@ lx-symbols command."""
         self.load_all_symbols()
 
         if hasattr(gdb, 'Breakpoint'):
-            if not self.breakpoint is None:
+            if self.breakpoint is not None:
                 self.breakpoint.delete()
                 self.breakpoint = None
             self.breakpoint = LoadModuleBreakpoint(
diff --git a/scripts/gdb/linux/tasks.py b/scripts/gdb/linux/tasks.py
index e2037d9..89d38e1 100644
--- a/scripts/gdb/linux/tasks.py
+++ b/scripts/gdb/linux/tasks.py
@@ -18,6 +18,7 @@ from linux import utils
 
 task_type = utils.CachedType("struct task_struct")
 
+
 def task_lists():
     global task_type
     task_ptr_type = task_type.get_type().pointer()
@@ -38,6 +39,7 @@ def task_lists():
         if t == init_task:
             return
 
+
 def get_task_by_pid(pid):
     for task in task_lists():
         if int(task['pid']) == pid:
diff --git a/scripts/gdb/linux/utils.py b/scripts/gdb/linux/utils.py
index d7ff3a3..0893b32 100644
--- a/scripts/gdb/linux/utils.py
+++ b/scripts/gdb/linux/utils.py
@@ -151,6 +151,6 @@ def get_gdbserver_type():
             gdbserver_type = GDBSERVER_QEMU
         elif probe_kgdb():
             gdbserver_type = GDBSERVER_KGDB
-        if not gdbserver_type is None and hasattr(gdb, 'events'):
+        if gdbserver_type is not None and hasattr(gdb, 'events'):
             gdb.events.exited.connect(exit_handler)
     return gdbserver_type
-- 
2.1.4

[PATCH 6/7] scripts/gdb: Add ps command

[Jan Kiszka]

From: Thiébaud Weksteen <thiebaud@weksteen.fr>

Signed-off-by: Thiébaud Weksteen <thiebaud@weksteen.fr>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 scripts/gdb/linux/tasks.py | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/scripts/gdb/linux/tasks.py b/scripts/gdb/linux/tasks.py
index 89d38e1..3191f47 100644
--- a/scripts/gdb/linux/tasks.py
+++ b/scripts/gdb/linux/tasks.py
@@ -67,6 +67,22 @@ return that task_struct variable which PID matches."""
 LxTaskByPidFunc()
 
 
+class LxPs(gdb.Command):
+    """Dump Linux tasks."""
+
+    def __init__(self):
+        super(LxPs, self).__init__("lx-ps", gdb.COMMAND_DATA)
+
+    def invoke(self, arg, from_tty):
+        for task in task_lists():
+            gdb.write("{address} {pid} {comm}\n".format(
+                address=task,
+                pid=task["pid"],
+                comm=task["comm"].string()))
+
+LxPs()
+
+
 thread_info_type = utils.CachedType("struct thread_info")
 
 ia64_task_size = None
-- 
2.1.4

[PATCH 7/7] scripts/gdb: Remove useless global instruction

[Jan Kiszka]

From: Thiébaud Weksteen <thiebaud@weksteen.fr>

Signed-off-by: Thiébaud Weksteen <thiebaud@weksteen.fr>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 scripts/gdb/linux/tasks.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/scripts/gdb/linux/tasks.py b/scripts/gdb/linux/tasks.py
index 3191f47..862a4ae 100644
--- a/scripts/gdb/linux/tasks.py
+++ b/scripts/gdb/linux/tasks.py
@@ -20,7 +20,6 @@ task_type = utils.CachedType("struct task_struct")
 
 
 def task_lists():
-    global task_type
     task_ptr_type = task_type.get_type().pointer()
     init_task = gdb.parse_and_eval("init_task").address
     t = g = init_task
@@ -89,7 +88,6 @@ ia64_task_size = None
 
 
 def get_thread_info(task):
-    global thread_info_type
     thread_info_ptr_type = thread_info_type.get_type().pointer()
     if utils.is_target_arch("ia64"):
         global ia64_task_size
-- 
2.1.4